Piston pok inteknal-combustion engines



Dec. 4, 1923.,

K. Nl. MM'THEWS PIsToN FOR INTERNAL coMBUsTloN ENGINES Filed J lll insta-:lifted Dee. 4, i923.

PAEll llFlCE.

KINCHEN N. WIAT'IHEWS, 0F ST. LGUIS, TJIISSGURI.

PISTON FOR INTERNAL-COMBUSTION ENGINES.

Application filed July 15,

1I 'o all whom may concern.'

Be it known, that I, Kinofilm N. Mire 'ri-inws, a citizen of the United State-s, and residing at St. Louis, Missouri, have invented the new and useful Improvement in Pistons for Internal-Combustion. Engines, of which the following is a specification.

This invention relates to engines and more particularly to pistons for gas engines.

Gas engines are usually provided With removable heads for the cylinders in which the pistons reciprocate, and these pistons are almost universally of the trunlr type carrying Wrist pins connected by pitmen with the crank on the crank shaft. The crank and crank shaft rotate in a crank case which provides an oil Well so that the parts lare lubricated by the splash system. It is often necessary to remove and replace the pistons and Where it is necessary to dismantle the c "ink case to effect such removal or replacement, such operation involves considerable time, labor and expense.

One of the objects of this invention, therefore, is to provide a piston which is adapted for removal through the head end of the cylinder Without disturbing the connecting` rod or pitman or the crank case.

Another object is:v to provide a piston of the type described, in which the piston is .firmly and reliably retained and fastened., but which fastening means is so constructed. as to permit ready detachment.

Another object is to provide a piston of the type described, in which the cooling thereof is i sured by the splashing of the lubricant.

Further objects will appear from the detail description taken in connection with the accompany r drawing, in Which:

Figure 1 a longitudinal vertical section through the cylinder of a gas engine showini;A the piston embodying this invention;

Figure a section on the line 9-2, Figure l., slimving more particulmly the core or carrier; and

ligure 3 is an enlarged detail, part in section. showing the fasteners.

Referring to the accompanying` drawing, l designates the cylinder of any suitable type of engine having a removable cylinder head 2 and crank case sections 3 and Il. A crank shaft 5 has a crank 6 thereon to which is attached a pitman or connecting rod 7 clamped at its other end on a wrist 1920. Serial No. 396,606.

pin 8. The parts so far described may be of any suitable or usual construction.

' The piston is of the trunk type and comprises an outer shell 9 of cast iron thickened near its head end at 10 topi-Ovide grooves for piston rings 11. The shell is moreover of symmetrical form and is machined both inside and outside so as to provide a cast iron structure of minimum` Weight.

Arranged to lit into this shell is a core or carrier'comprising spaced annular parts or rings 12 and 13 connected by Webs 14, which have bosses 15 for the ends of the Wrist pin 8 and Which bosses are further connected With the annular parts 12 and 13 by vvebs 16. The upper ring has formed thereon vertically extending bosses 17 which are further braced from the bosses l5 by Webs 18. The core is formed of any suitable material, such as aluminum or aluminum alloyv` and this core is finished externally so as to fit accurately but slidingly Within the shell.

The shell and core are secured together by fastening means comprising screvv fas'- teners 21 passing' through the head of the shell and threaded into the bosses 17, and each fastener has a head 22 as to be operable from the head of the piston. The fastener is formed hollow, and is provided with a coned end face 28 and is split for a short distance as shown at 2t. The bottom of the tapped holes in each boss 17 is pio vided with a tapering` projection formed by a suit-able boring; tool and the tip of this projection has a diameter slightly less than the normal internal diameter of the tip of the fastener. A s the fastener is screwed down to connect the shell With the boss, the tapering;q projection 25 engaged by the tip of the fastener will cause this fastener to spread so to cause a {ii-1n gripping engagement between the fastener and the core. which will serve to lock this fastener against becoming accidentally loosened during); the reciprocation of the piston in the cylinder. .lifter the shell has been placed on the core and the two parts secured together bythe fasteners 2l, they will in fact become one so that the pistou Will be firmly connected With the pitman to reciprocate in the cylinder and operate the crank shaft. On account of the skeleton construction of the core, however, exposing the piston shell, the latter is subjected to the splash ducted to the core Which will act as a radiator to radiate the heat and transmit it to the splashing lubricant.

When it is desired to remove the piston shell, the cylinder head is removed and the fasteners 2l are loosened by engagement of the heads 22 thereof by a suitable Wrench, thereby permitting removal of these fasteners from the head end of the cylinder. After the fasteners are removed, the shell can be rotated through a part of the revolution until the holes yin the head of the piston clear the bosses -17 when the piston shell can be removed by hooks inserted through these holes. The shell can, therefore, be removed froinrthe cylinder Withoutdisturbing the connecting rod or the crank case,` Furthermore the replacement of the piston shell can be accomplished iii the same manner and the cylinder head can then be replaced.

-It is obvious that Various changes may be made in details of construction Without de- Parting from the Spirit Of this invention; it is, therefore, to be understood that this invention is not to be limited to the specific details ,Shawn and described Having thus described the invention, what is, .Claimed iS= l. A trunk piston, comprising, an outer shell forming the head and side Walls of the piston, an inner core having Wrist pin bearings, said shell fitting loosely over said core in order to permit endwise removal of said shell therefrom, a fastener passing through the head of said shell and into said core and accessible for manipulation'from the head end thereof, and locking means at the core end .of said fastener adapted to secure it in position, said locking means being retained so as to permit manipulation of said fastener. V

2. A trunk piston, comprising, an outer shell forming the head and side walls of the piston, an inner core having Wrist pin bearings, said shell fitting loosely over said core in order to permit endwise removal of said shell therefrom, a fastener passing through the head of said shell and into said core and accessible for manipulation from the head end thereof, and means for locking the core end of said fastener within said core, said locking Vmeans being retained so as to pei mit manipulation of said fastener.

3. trunk piston, comprising, an outer shell forming the head and side Walls of the piston, an inner core having Wrist pin bearings.. .sin shell fiifiingiioili Said in order to permit cndwise removal oi." said shell therefrom. fastener pa. ing through the head of said shell and into said core and accessible for manipulation from the hcad end thereof, and cooperating locking means on said fastener and said coro adapted to sccure said fastener and permit manipulation thereof.

4. A trunk Jiston, comprising, an outer shell forming tlie'hcad and side walls of thc piston, an inner core having wrist pin bear* ings, said shell fitting loosely over said core in order to permit endwise removal of said shell therefrom. a fastener passing through the head of said shell and into said core and accessible for manipulation from the head end thereof, and means on said core adapted for co-operation With said fastener adapted to secure the same and permit manipulation thereof.

5. ln an engine having a cylinder and a crank case leading therefrom providing for splash lubrication, a piston, comprising, an outer shell, and a core therein having spaced annular parts arranged to expose said shell but adapted to engage the side walls of said shell at'spaced points therealong.

6. In an engine having a cylinder and a crank case leading therefrom providing for splash lubrication, a piston, comprising, au outer shell, and a core therein having spaced annular parts arranged to expose said shell but adapted to engage the side walls of `said shell at spaced points therealong and having lugs adapted to engage the head cud of' said shell. i

7. In an engine having a cylinder and a crank case leading therefrom ln'oviiding for splash lubrication, a piston, comprising, an outer shell, a core therein having spaced :1unular parts arranged to expose said shell but adapted to engage the side walls of said shell at spaced points and having lugs adapted to engage thehead end of said shell, and fasteners passing through said shell and into said lugs.

8. In an engine having a cylinder and a crank case leading therefrom providing for splash lubrication, a piston, comprising, :in outer shell, a core therein having spaced annular parts arranged to expose said shell but adapted to engage the side walls of said shell at spaced points and having lugs adapted to engage the head end ol' said shell, fasteners passing through said shell and into said lugs, and means for looking said fasteners in said lugs.

In testimony whereof I atlix my si, {nat|1r(` this 6th day of July, 1920. i

KINCHEN N. MATTHEW 

